Spark-plug.



A. C. F'ERRIER.

SPARK PLUG.

APPLICA y 24, l'dlfi- 1,169,628. Patented Jan. 25, 1916.

I k P UNITE STAES PATEOFFICE.

ALBERT C. FEBRIEK, OF LINCOLN, NEBRASKA, ASSIGNOR OF ONE-HALF T0 WILLIAM J. HILL, OF LINCOLN, NEBRASKA.

SPARK-PLUG.

Application filed May 24, 1915.

To all whom it may con ern Be it known that I, ALinsirr (7. Yamaha, a citizen of the. United States, residing at Lincoln, in the county of Lancaster and State of ,Xcl'jraska, have invented certain new and useful improvements in Sparkllugs, of which the following is a specification.

This invention relates to an improvement in spark plugs, and has for its object to provide such a construction that the carbon produced by burning gas will be auto-- niatically removed from the comluctor and insulating plug and from the chamber con taining these parts. to present the formation of a short circuit between the electrical con ductor and the ground electrode of the spark plug.

The invention consists of the novel construction, combination and arrangement of parts as described herein and claimed, and as illustrated in the accompanying drawing, whercin,

Figure 1 is av view of the spark plug in longitudinr section. Fig. 2 is a broken away detail showing parts of the device on an enlarged scale.

Referring to the drawing fora more particular description, numeral 3 indicates the wall of an engine cylinder within which charges of gas may be delivered to be ignited or exploded by means of the spark plug, the. electric charge passing from the finger a of the conductor 4 through the gap to the ma tallic finger 5 which is mounted in the liou's ing or ground electrode 6. V

In the use of spark plugs as ordinarily constructed, carbon will be. deposited on the stem oftheinsulating plug and will adhere thereto, and from continued use the do; posits often accumulate to such an extent that they form an electrical conductor be" tween the metallic partsot the cylinder an the conductor 4 so that the cl'iargesmf gas will not be ignited, with the result that fre" quent removals of the spark plug from the cylinder, for pur poses of cleaning the parts, are required.

vIn the present instance the insulating plug 7 is provided with an annular stem 8 which is formed convergent, preferably, from its inner end 5 to its terminal, its finger a roi cting inwardly of the cylinder Wall in hr) with the longitudinal axis of the plug. 'l'hc metallic part or electrode 6 is providel Specification of Letters Patent.

Patented Jan. 25, 1916.

Serial No. 30,032. i I

with a chamber 0 in communication with the interior of the engine cylinder 3, a cylindrical passageway 9, preferably of uniform diameter. being provided which opens thereon and which communicates with said chamher 0. Chamber 0 is formed convergent toward the passageway 9 preferably its entire length. The insulating plug is adapted to be disposed witlrits stem traversing the chamber (a centrally with its finger a disposed centrally of the passageway 9, and as thus described an annular space or container 10 will be provided between the walls of members (3 and h which will be conver gent toward the terminal of the steni8, the degree of com-ergenec increasing gradually throughout its entire length; and the area in rross-section of said chamber or container 10 constantly decreases in a direction of the terminal of said stein.

in operation, the force of the explosions of ignited within the container 10 which successively occur will prevent accumulation of deposits of carbon upon the stem 8, and since the area of the container, transversely considered. is greatest at or near its end remote from the cylinder 3, the contents of the container 10 will move. into the engine cylinder with force sullicient to maintain the passageway 9 in a condition substantially free from deposits. 7

Numeral 1]. indicates a terminal constricted part of the container 10, communicating with the cylindrical passageway 9. While it is formed convergent toward the passageway 9, the wall of the stem 8 is equidistant, transversely considered, from the wall of the metallic housing-6, throughout bon from the stem 8 and removal of the carformed convergent from its inner end to its terminal and provided with an electrical conductor, said insulating plug being adapted to be disposed with its stem traversing the chamber of said metallic part to form an annular, convergent chamber circumscribing and extending the entire length of said stem, the degree of convergence of said chamber increasing throughout its entire length in a direction of the terminal of said stem.

2. A spark plug, comprising, in combination with a cylinder, a metallic part having a chamber communicating with the cylinder, an insulating plug provided with an electrical conductor and having a cylindrical stem formed convergent toward its terminal, said insulating plug being disposed with its stem traversing the chamber of said metallic part to form an annular chamber extending substantially to the end and circumscribing the stem with a gradually increasing degree of C011. crgence toward the terminal thereof.

3. A spark plug, comprising, in combination with a metallic part having a longitudinally convergent chamber, an insulating plug having a cylindrical stem formed con vergcnt from its inner end to its terminal and provided with an electrical conductor, said insulating plug being adapted to be disposed with its stem traversing the chamber of said metallic part to form a chamber gradually decreasing in area and extending substantially to the terminal of said stem.

4. A spark plug, comprising, in combination with a cylinder, a metallic part formed with a convergent chamber and a cylindrical passageway opening on the cylinder and said chamber, an insulating plug having a convergent stem and provided with an electrical conductor having a projecting finger disposed in line with the longitudinal aXis of said stem, said insulating plug being disposed with its stem centrally traversing said chamber to provide an annular chamber having an area in cross-section constantly decreasing from the inner end of the stem touurd the cylindrical passageway, the electrical conductor being disposed centrally of said cylindrical passageway.

5. A spark plug, comprising, in combination with a. cylinder, an electrode formed with a coiwergent chamber and a cylindrical passageway opening on the cylinder and communicating with the chamber, an insulating plug having a convergent stem and provided with an electrical conductor having a finger extending beyond the stem, said insulating plug being disposed with its stem traversing and terminating substantially at the end of said chamber with its finger disposed centrally of the cylindrical passageway, a longitudinal part of said stem, adjacent to its terminal, being disposed equidistant from the wall of theelectrode to provide a constricted passageway opening on said cylindrical passageway.

In testimony whereof, I have affixed my signature in presence of two witnesses.

ALBERT C. FERRTER. Ni tnesscs l'VlLLiAM J. HILL, Minn e K. HUMPHREYS. 

